MSI silent installation fails with code 1603

So you have a product that has an MSI installer and installation works perfectly. But you want to install the product using the /quiet flag, so that you automate the installation or for whatever reason and now it fails all the time. First of all, do the normal thing when you have an MSI installation error:

• Install the package by manually running msiexec and add verbose logging: msiexec /i My.Setup.msi /L*VX theinstall.log ... (your extra parameters, including /quiet here)
• Open theinstall.log file and look for the string "Value 3" which is the line where the install actually failed
• See if you can see what caused the fail

My setup would take properties from the registry and only need the user password to be supplied, so I used it like this:

msiexec /i My.Setup.msi /L*VX theinstall.log /quiet USERPASSWORD="thepassword"

For me, the reason for the failure was very unclear: "CreateUser returned actual error code 1603". I had the user, I had the password, what was going on?

The solution was to add ALL the properties needed. With a silent installation, it seems some of the actions in the UI are ignored. It's not just quiet, it's skipping things. In order to get a list of all possible properties, open the same install log and look for "SecureCustomProperties", which should list all the properties that you can set from the command line, separated by semicolon. I am sure I didn't need to set them all in order to work. In fact I didn't. I only used the ones used in the UI.

Hope it helps.